I have seen a few ways to latch down the rear louvers and since one member is working through this now I wanted to throw out a few ideas that I have seen or believe that would work. Feel free to add what you have done.
1. Hood pins. Let's face it they aren't always pretty but they work. Quick-latch.com sells some sleek ones but you do pay for them.

2. Stainless catches. Typically used for cabinets but they can hold well and are small enough to not be an eye sore. Just search Google for options using "stainless catches." Some are even have adjustable tension.
Here are a few that jumped out.

1. Hood pins. Let's face it they aren't always pretty but they work. Quick-latch.com sells some sleek ones but you do pay for them.

2. Stainless catches. Typically used for cabinets but they can hold well and are small enough to not be an eye sore. Just search Google for options using "stainless catches." Some are even have adjustable tension.
Here are a few that jumped out.

